Barber Pole Effect

Barber Pole Effect is referring to the visual illusion which is observed when the diagonal stripes on a barber pole turns on its vertical axis appear to move upward instead of turning with the pole. This effect is caused by the vague contour of the pole which attributes the direction of movement to the shape of the apertures or gaps which the stripes make. This means that our perception of motion tends to be biased in favor of the longer axis.